Maestin david geeenwood



2o of three ovens, one of which shows all the UNITED STATES PATENT OFFICE@ MARsTIN DAVID GREENWOOD, OF Hoogsrck FALLS, NEW YORK.v

OVEN FOR `ANNEALING METALS.

SPECIFICATION formingpart of Letters Patent No. 376,740, dated January y24. 1888. l

` Application tiled August 3l, 18H6. Serial No. 212,321.7 (No model.) l

. .To all whom it mrtg/*concern- Beitknown that I, MARstrrN DAVID GREEN- WOOD, a citizen ofthe United States, residing y at Hoosick Falls, in the countyof Rensselaer and State of New York, have invented a new and useful Improvement in the )Construction Y and Operation of Ovens for Annealing Metals;

and I do declare the following tobe .et-full,

ings, making apart of this specification, in

which- Figure l is a View in perspective of the oven complete and Vthe lower portion of the smoke-stack or chimney. Fig. 2Jis a View in' perspective of the escape-pipe and its connection with the oven, wlth'the door'opcmand the cover which closes the hole between the oven and the pipe. Fig. 3 is a view in perspective of the cover. Fig. 4 is a plan view dues, the arrows indicating the direction which the air takes while passing through the dues, another showing the lues left out, with the arrows indicat-ing the direction ofthe current, and the third showing the outside casing of the oven and the escape-pipe. This lView also shows the connection between the ovens and the chimney. Fig. 5 is a View in per' section, showing the interior of the oven.

To enable others skilled in the art to make and use my invention, I will proceed to describe the same with reference to the drawings, in which similar letters of reference designate like parts. l n

A is the oven, with antarched top and a cylindrical hole communicating with the lower end of the chimney or escape-pipe b. The bottom of this small chimney or escape-pipe is made larger than the top, and the upper portion,`c, is connected with the larger or lower portion by a tapering joint, I), and the lower part of the pipe ts over a ring of firebrick, b, and its lower edge rests on the ring a', which forms a portion of the arch or top of the oven.

a is a door at the bottom of the escape-pipe,

(shown in Fig. l as closed and in Figs. 2 and 5 as open,) which is for the purpose of allowing the cover a to be inserted and removed.

O on the end of the oven is where thematerial to be annealed is put in and taken out.`

On cach side of the oven I provide one or more res. I have showntwo in the dra-wings at d d.

d is the grate on which the coal isl burned,1

and di the doors where the coal is put in the fire.

The re communicates with the oven, in which `the pots containing the metal tofbe annealed are placed,by the openings d5, andthe i dl is the ash-pit extending. under the grate.-

ings e2 in the bottom of the floor of the oven Y into the channel or tlue E2, underlying the oven and communicating with theV pipe E, which leads to the main stack or ychimney D. The

Abranch of this .pipe Eis provided `with a damper or cut-offf, which can-be used to out off the draft from thetmain-chimney D, when desired, from either of the series of ovens.

aand when in place and set with fire-clay serves to close the opening between the oven Y and the pipe b when the annealing process is The door a at the bottom of the going on. pipe can be opened in order to putin and take out the platen or cover, as wellas to admit air for theventilation of the room.

This specification is drawn withl reference to the application of my invention to the an'- nealing of castings to produce what isgknown as ,malleable iron,77 and is most useful inA foundries where more than one oven is used.

Heretofore ovens have been constructed with a direct connection between the oven and the tall chimney or stack, to give draft tothe fire, and when the product hasbeen sufficientlyv annealed, the tire' withdrawn, and the receiving end opened the cold air Vwill be drawn oven is used; but when two or more ovens are amount of draft, and the fires must be kept up longer to anneal the product than when each oven is allowed to cool by itself, as in my construction. I connect the main chimney or stack with each of the ovens separately, and when the fire is shut oft by closing the damper f there is no air entering the main stack throughtheoven. Whentheopeningisclosed by the platen, the draft of the main smokestack will keep up the heat by supplying air tothe fire. At this time the door a is left open, which ventilates and serves to keep the oven-room cool. Vhen the metal is suiliccntly annealed to be removed, the dre is withdrawn, the fire-box closed up, the platen removed, and the door a closed. The end of the oven being opened at C, the cold air will be admitted into'the oven and be drawn up through the pipe b, (which can be made of any desired height.) The due E bei ng closed by the damperf, no cold air will be admitted to the main stack D, and the draft in the ovens in which the process of annealing is going on will not be decreased by the cooling of the oven which is open.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is-

A series of annealing-ovens, each oven provided with a separate pipe communicating directly with astack common to allthe ovens, a damper in each pipe adapted to open and close the communication between each oven and the common stack, a separate chimney in each oven,also provided with a damper, and an opening in the lower portion of the oven, through which the cold air from the outside of the oven is adapted t0 be drawn through the oven and through the separate chimney in the top of each oven, whereby the cooler air, passing from the oven in which the annealing process is completed, does not diminish the draft of the main stack common to the ovens, substantial-ly as and for the purpose specified.

M'RSTIN DAVID GREENWOOD. 

